Reply to Cue points getting deleted instead of playing.

This happens seemingly randomly, but I'll be in the middle of a mix and have one loop going (while in juggle mode), then, when i press a button to jump to a different cue point, the cue point just gets deleted instead of the music jumping to that cue point. this can be a huge problem O_O. It's as if I shift+pressed the cue button but I didn't hold shift at all. what's going on?